Material handling system



Feb. 20, 1951 D, L, MjLLAR 2,542,203

MATERIAL HANDLING SYSTEM Filed Nov. 12; 1946 DW/G/IT L MILL/1R Patented Feb. 20, 1951 UNITED STATES PATENT oFFlce 8 Claims.

My invention relates to systems for handling items of manufacture during the manufacturing process.

In finishing up or completing various articles of manufacture, or commodity pieces it becomes necessary to put them through certain finishing processes. These processes vary according to the article being treated, and with each variation in process, a different treating time is usually necessary.

For instance, the processes necessary for finishing a single article may include: removal of grease or oil; washing; drying; sizing; drying; paint dipping; initial drying; baking; and cooling. These processes are more or less standard for most articles which are surface coated with baked enamel, but when different kinds of baked enamel are desired, the time of initial set, baking, etc. usually varies.

In order to surface finish other articles, an entirely different set of processes may be required. For instance in metal plating, the required steps may include: removal of grease; drying; acidizing; submergence in the plating bath, washing; and again drying.

In other words, each step in any sequence of process function usually entails a different time element from the other steps in the process, and likewise, similar steps in different processes on different articles may vary in time required.

It is the principal object of the present invention to provide a treating or finishing system, by which the articles of manufacture or commodity may be continuously carried by an endless conveyor through treating units or areas capable of performing the desired process steps, the mecha nism of the system being so arranged that the time requirement for accomplishing each step may be complied with.

Another object is to provide a system of this class, so designed that it is adaptable to any desired number of steps in the various processes.

A further object is to provide a conveying system, for articles of manufacture, which may be easily varied to accommodate articles of many different sizes, weights, and shapes.

An additional object is to provide a conveying system which gyrates the articles being processed, so that a surface coating will not flow to or build up at various superficial points on the article, such gyration resulting in the elimination of lumps, bumps, or fatty edges, and in accomplishing a smooth and even surface coating.

A still further object of the invention is to provide a conveyor-type treating system which requires a minimum of floor space in comparison Each of the drums has to the volume of articles accommodated thereby.

Other objects will be apparent from the following description, when taken in conjunction with the accompanying single sheet of drawings, wherein:

Figure 1 is a perspective view of a material handling system assembled in accordance with the present invention;

Figure 2 is a sectional view taken substantially on a vertical plane indicated by the linen-2 of Fig. 1;

Figure 3 is a sectional view taken substantially on a vertical plane indicated by the line 3--3 of Fig. 1;

Figure 4 is a side elevational view taken from a position indicated by the line 4-4 of Fig. 1;

Figure 5 is a fragmentary perspective view detailing the construction of one of the conveyor guide-rollers;

Figure 6 is an enlarged perspective view detailing one type of spring clip which may be used for attaching an article to the conveyor band; and,

Figure 7 is a similar view detailing a different type of clip.

Like characters of reference designate like parts in all of the figures wherein they occur.

In the drawings:

The reference characters A, B, C, D, E and F each indicate, as a whole, one of a plurality or bank of preferably hollow or tubular drums. an axial shaft l which projects beyond both of its ends, and each protruding end of each shaft is journalled for rotation in asuitable bearing 2 mounted upon a horizontal sill 3. There are two of the sills 3 lying parallel to each other, and these sills may be rigidly supported a desired distance above a floor surface by any suitable means. In the present instance, the sills are shown as being carried by the upper edge portions of a plurality of aligned vessels, tanks or chambers, each of which is designed to accomplish within its interior one step of a process, as is more fully described hereinbelow.

In Figs. 1 and 4 of the drawings, the chambers are consecutively numbered H), H, l2, l3, M and I5, and the chambers respectively support the drums A, B, C, D, E and F.

As best illustrated in Fig. 4, there is provided between each adjacent pair of drums an idler roller 20, which extends between the sills 3, and which is journalled for rotation with relation thereto. The ofiice of the idler rollers will be more fully described hereinbelow.

In considering the battery of drums and chambers, as a whole, the drum A and its chamber l might well be termed the first or front treating unit of the series, and the drum F and its supporting chamber l should be considered as the last or rear unit of the series.

Adjacent the front portion of the periphery of each drum, there is provided a horizontal stationary shaft 2| having its two ends rigidly mounted shaft 2|. The lengths of the sleeves 24 may be varied as desired, to'selectively position the discs 23 at various distances from each other, and also to position them at desired points with relation to the shaft 2|, and consequently in desired positions with relation to the adjacent drum.

The apparatus further includes a flat table 25 supported at the front end of the battery of units upon front legs 26 and rear legs 21. I The particular type of table support is optional, but in the present instance the legs are illustrated asbeing formed of angle iron.

In utilizing the successive units of the battery in carrying out the various steps of a given process, as set forth hereinabove, it is desirable that the pieces of work being processed be transported into and out of the chambers successively. It is also desirable that the pieces of work reside within each chamber for certain periods of time, according to the type of the work piece, and also according to the nature of the step of the process which is to be accomplished within the individual chamber..

,In order to properly convey the work pieces through the various chambers, the following described apparatus is provided:

One of the legs 26 at the forward end of the table is equipped with two horizontal forwardly projecting arms 28, each of which rotatably supports a sheave 29. The rear end of the sill 3 has two arms 30, each of which supports a sheave 3| similar to the sheaves 29.

An endles belt -33 extends between the front sheaves 29, its upper extent passing over the upper sheaves 23 and rearwardly along the upper surface of the table 25,, over the end one of the rollers 24 carried by the front horizontal shaft 2|, and over and around the first drum A. The first convolution of the belt aroundthe drum A is brought forwardly to pass in front of the second roller 24 on said front shaft 2 I, and again returns rea-rwardly to pass over and around the drum A. The winding of the belt 33 about the drum A and in front of the consecutive rollers 24, is continued until the other end of the drum is reached. After the last convolution of the belt passes in front of and over the last one of the rollers 24 on the front shaft 2 l, the belt extends horizontally to the top of the second drum B. From this point, the belt 33 is repeatedly wound helically around the drum B, and around the front urface of each consecutive one of the rollers 24, being carried by the second, or next to the front one, of the shafts 2 until the last convolution around the drum B is at the near end sired, some of the drums may not be encircled at all. The convolutions are arranged to suit the particular process being accomplished, as will be more fully explained hereinbelow.

After the belt 33 is wound a desired number of times around the rear drum F, it passes rearwardly over the top of the uppermost sheave 3|, and then downwardly .and beneath the lower sheave 3|, from whence it returns to the lower sheave 29 at the front end of the apparatus.

As a means for attaching pieces of work to the belt 33, some suitable clamp or spring clip is fas-' tened to the belt. Clips suitable for some pieces of work are shown in Figs. 6 and 7, and are indicated respectively by the reference numerals 34 and 35.

In Fig. 3 is shown a typical arrangement of tank and drum for use in processes in which the work pieces, which are indicated by the reference numeral 36, are to be dipped in a body of liquid. For instance, for de-greasing,- painting, sizing, or the like. In this arrangement, the tank H! has an arcuate bottom 31 which supports a body 38 of treating liquid.

In Fig. 2 is shown a pair of treating units which may be used for drying or baking the work pieces 38. These units could well be the last two steps of the process, and could be carried on within the two chambers l4 and I5.

In this case the chambers are equipped'with removable lids or tops 39 which, along with the arcuate bottoms 31, completely enclose the drums E and F. A fuel inlet pipe 40 is provided within each chamber beneath the drum therein, so that a fire 4| may be applied to the nether surface of the bottom 31. I

It is anticipated that any one of the chambers, tanks or compartments III, II, l2, l3, H or l5 may be so constructed that a suitable process step may be accomplished therein. Y

A power unit 42 may be provided at any desired point to drive the belt 33.

In operation, a feeder stands at the table 25, and attaches work pieces to the clip holders 34 as they pass in front of him. The point of attachment of the work pieces is indicated by the arrow 43 in Fig. l.

After being thus attached to the belt 33, the work travels with the belt around the various drums, behind the rear sheaves 3| and returns to the table 25 over the uppermost sheave 29. A

second worker stands at the table 25 and removes the work pieces from the clips at the point indicated by the arrow 44.

As stated hereinabove, the convolutions of the .belt 33 around the various drums may be varied at will, so that the work will be held in the various chambers the correct time to accomplish therein the specific step of the process.

In cases in which it is desired to expose the work pieces to the open atmosphere, possibly for drying, one or more of the drums may be bypassed by the belt. If such drying proces re-. quires more time, the belt may be made to travel around a drum or drums in which no liquid body is provided. If still more drying facilities are needed, certain ones of the chambers may be equipped for heat application.

of the drum, as viewed in Figure 1. The belt continues in this manner to encircle desired ones of the drums. The number of belt convolutions placed around each drum is elective, and if deprocess.

In surface coating articles by the conventional dipping process, there is ordinarily one last drop of the coating material which fails to drain off of the article. If this last drop or tear is not dispensed with before the coating material is permitted to take its initial set, it results in the formation of a lump on the surface of the finished product. This last drop is, of course, made up of an excess of the coating material, that portion of the coating material which falls to adhere to the article.

Under the handling system of the present invention, this excess of material is allowed to gravitate from its original point of formation, back over the surface of the article, and to therefore spread out evenly over such surface before sufficient time has elapsed for the material to take its initial set. It therefore becomes unnecessary, under the present system, that any separate and specific step be taken to remove, smooth out, or otherwise dispense with this last drop of excess coating material. A perfectly smooth coating surface is therefore obtained.

Under the system of the present invention, when the articles are passed through a baking chamber or oven, the heat is applied equally to all of the articles, and to all parts of each article. This is because all articles not only spend an equal amount of time within the baking chamber, but they each spend an equal amount of time in their various positions within the chamber. Therefore, they each receive the same amount of baking, even though the heat is not equally distributed within the oven.

Attention is called to the fact that the apparatus is capable of great versatility in arrangement, and can be made to accomplish numerous and various consecutive steps in processes of various arts. I therefore do not wish to be at all limited to any particular process. or to the handling of any particular type of work pieces.

It is pointed out that although the drums all rotate in unison, they may also rotate independently of each other, and although the drums shown in the drawings are all. of identical diameters, it may in some instances be desirable to make some of them smaller than others in the series.

Obviously the device is susceptible of various changes in arrangement and specific structure without defeating its practicability, and I therefore do not wish to be confined to the specific embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claims.

I claim:

1. A conveyor system including: a series of cylindrical rotatable drums on independent horizontal axes; an endless band helically wound around each drum in the series; and means for spacedly attaching articles of manufacture to the band.

2. Structure as specified in claim 1, and means adjacent each drum for guiding the band so that each convolution thereof around the drum remains spaced from the next adjacent convolution.

3. Structure as specified in claim 2, in which the guiding means includes: an independently rotatable element spaced from each drum, and over which the band must pass; and fianges on the element for limiting lateral movement of the and.

4. Structure as specified in claim 3, and means associated with each drum for performing an operation upon the articles carried by the band.

5. Structure as specified in claim 1, and means associated with each drum for performing an operation upon the articles carried by the band.

6. Structure as specified in claim 1, in which each attaching means includes: a spring clip attached to the band.

7. A conveyor system including: a rotatable drum; an endless band helically wound around the cylindrical drum; means for controlling the spacing of the convolutions of the band around the drum; means for spacedly attaching articles to the band; and means associated with the drum for performing an operation upon the articles carried by the band.

8. Structure as specified in claim 7, in which the controlling means includes: an element spaced from the drum and adjacent which the band must pass; and means on the element for limiting lateral movement of the band.

DWIGHT L. MILLAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 928,172 Bernardin July 113. 1909 1,010,720 Broderick Dec. 5, 1911 1,523,971 Johnsen Jan. 20, 1925 1,831,330 Thompson Nov. 10, 1931 1,837,502 Thompson Dec. 22, 1931 2,108,285 Forrest Feb. 15, 1938 2,115,025 Kline et al Apr. 26, 1938 2,214,262 Tood Sept. 1.0, 1940 FOREIGN PATENTS Number Country Date 833 Great Britain Jan. 12, 1911 698,360 Germany Nov. 8, 1940 

